1. Field of the Invention
This invention relates to a document processing system which displays pages of a document in overlapped relation and in particular to a tag display control system which avoids overlap display of tags attached to a document.
2. Description of the Related Art
Hitherto, in a document processing system which displays documents as multiwindows on a display screen and processes the documents in page units, an art for attaching tags to document pages to enable easy retrieval of any desired page has been proposed (Information Processing Society, 38th National Conference Lecture Paper Collection (II), p1096-p1097, "Actipedia-electronic book (ACTEK)", Hidekazu TANIKAWA, el at.).
In a document processing system capable of multiwindow display, an art has been proposed in Japanese Patent Unexamined Publication No. Hei. 5-40594, wherein in addition to attaching tags to document pages, a tag window is linked with a document page and can be extended off the document page for attachment thereto and even if document pages are displayed in overlapped relation, the tag extension is displayed.
According to the proposed art, if document pages are displayed in overlapped relation in a bundle, any document page can also be easily retrieved with the tag displayed extending off the document pages.
However, if tags are extended off document pages for attachment thereto as described above, when document pages are displayed in overlapped relation, the tag attached to a lower page may be hidden under the tag attached to an upper page. In such a case, the tag to the lower page is not displayed and the page cannot be retrieved.
To display document pages in offset overlapped relation for representing thickness of a bundle of the pages, the tag to a lower page may be hidden under an upper document page itself, causing a problem as described above. Such a situation also occurs when portrait and landscape document pages are mixed for display in overlapped relation; the tag to a lower page is hidden under an upper document page itself depending on how the document pages are overlapped.